Evaluating a novel biodegradable lattice structure for subtropical seagrass restoration

Abstract While attention in coastal ecosystem restoration has increased over the last two decades, the success rate of efforts remains relatively low. To increase success rates, physical restoration techniques often utilize supporting or protective materials to provide a stable surface for transplantation, and in some cases reduce herbivory and hydrodynamic disturbances. In this study, we evaluated the effectiveness of traditional (staples, burlap) and novel (BESE- elements, a biodegradable potato starch lattice) physical restoration techniques on the growth of transplanted Halodule wrightii seagrass. A first experiment revealed that seagrass planted in both two-stacked BESE structure without planting holes and four-stacked BESE with holes had significantly higher shoot count and blade length than four-stacked BESE without holes, with the latter design losing all seagrass shortly after deployment as shoots could not float through the structure. In a second experiment, the BESE lattice treatment (four-stacked with holes) had three times the shoot count and equal to greater blade length compared to traditional methods of physical restoration (staples and burlap), likely due to BESE providing some protection from hydrodynamic activity. However, disturbances, possibly including herbivory and hydrodynamic activity (culminating with Hurricane Irma), prevented long term study, illustrating the importance of stochastic abiotic factors in seagrass planting success. Overall our study demonstrates the effectiveness of using BESE lattice designs and similar physical techniques in the restoration of seagrass beds.